1. Field of the Invention
The present invention relates to an electronic component involving a two-terminal device, in which a piezo-electric device utilizing the piezo-electric effect is installed on a circuit board. More specifically, the present invention relates to an electronic component involving a two-terminal type piezo-electric device, in which the connection of the terminals to the piezo-electric device is facilitated by the terminals (connected to the piezo-electric device), lead wires extended from the terminals, and a supporting means for supporting the piezo-electric device, thereby firmly maintaining the connection state so as to upgrade the reliability of the electronic component.
2. Description of the Prior Art
Generally, a piezo-electric device resorts to the piezo-electric effect, i.e., to a mutual converting function between the electric energy and the mechanical energy. Thus the piezo-electric device serves as the operation source for reference signals of a microprocessor. This piezo-electric device is mostly used on electronic apparatus such as pagers, mobile communication means, televisions, audio sets and the like. At present, its demand is speedily increased. The method for manufacturing an electronic device involving the piezo-electric device includes the steps of: manufacturing a piezo-electric device; forming electrodes by depositing and patterning an electrode layer on the surface of the piezo-electric device; installing the piezo-electric device on a circuit board; and dotting, epoxy-coating and marking the device. The piezo-electric device and the terminal component are coupled together by soldering, and then, molding is carried out to form a packaged electronic component.
Japanese Utility Model Publication No. Hei-3-28596 discloses a two-terminal piezo-electric device in which the terminals mutually face each other from both sides of the piezo-electric device so as to connect the piezo-electric device.
FIG. 1 is a perspective view of the critical portion of a conventional two-terminal piezo-electric device. FIG. 2 is a front view showing the constitution of the entire portion of the conventional two-terminal piezo-electric component. FIG. 3 is a top plan view of the piezo-electric component of FIG. 2.
As shown in FIGS. 1 to 3, the above described two-terminal piezo-electric component includes: a piezo-electric device 4 having electrodes 2 and 3 installed on different faces of a piezo-electric substrate 1; and two terminals 5 electrically connected to the electrodes 2 and 3 of the piezo-electric device 4. The above described two-terminal piezo-electric component further includes a planar lead portion 11 lying on the same plane as both of the side surfaces of another lead portion 11 so as to constitute the two terminals 5. A supporting portion 14 is formed integrally with the lead portion 11 and has U shaped side openings for supporting both ends of the piezo-electric device 4. A stopper portion 15, bendingly formed near the boundary between the supporting portion 14 and the lead portion 11, blocks the greater part of the lower portion of the opening to prevent the movement of the piezo-electric device 4 toward the lead portion 11. The supporting portion 14 is electrically connected to the electrodes 2 and 3.
In the above described two-terminal type piezo-electric component, as shown in FIGS. 1 to 3, the piezo-electric device having the electrodes 2 and 3 is electrically connected to the two terminals 5. The piezo-electric device 4 is supported by the two bent portions of the supporting portion 14 which is connected through the stopper portion 15 to the lead portion 11. The stopper portion 15 is formed in a rectangularly bent contour between the supporting portion 14 and the lead portion 11. The stopper portion 15 substantially closes the lower opening of the supporting portion 14 so that the movement of the piezo-electric device 4 in the lower direction can be prevented. Thus, the piezo-electric device 4 which is supported by the supporting portion 14 is electrically connected through the electrodes 2 and 3 to the supporting portions 14.
However, in the above described two-terminal type piezo-electric component as shown in FIGS. 1 to 3, the stopper portion 15 cannot be actually rectangularly bent during the manufacture of the terminals 5. Accordingly, the lower opening of the terminal 5 cannot be perfectly closed, and the molten soldering material flows down during their coupling. Further, when the piezo-electric device 4 is placed into the U shaped supporting portions 14 of the terminals 5, the piezo-electric device 4 cannot be fixed in an accurate position.
Further, during the manufacture of the supporting portions 14 and the stopper portions 15 of the terminals 5, a planar strip has to be bent many times, with the result that the manufacturing work becomes difficult.